mothman3389

Hi everyone and thanks to all those who have contributed to this thread, it's been very useful over the last week. I have 2005 520d and have experienced the multiple dashboard warnings etc caused by the split hose. I dismantled it all last week, replaced the hose and everything seemed to be fine.
However yesterday the warnings reappeared and the back end gradually dropped. The compressor was not running at all. So, took it all apart again last night. After much checking of voltages and connection I decide to try the compressor by supplying direct from the battery. It ran fine and with the engine running the suspension pumped itself back up to the correct height. When it reached the correct height I heard the system try to stop the compressor and vent the excess air and I disconnected.
I am now confused.
Having run the compressor I now know that the compressor is good, the inlet hose and filter are fine, the discharge pipe, the distributer and the red and blue hoses to each side are ok. I also think that the level sensors on each side are good because a) I get the warnings so the system knows it's in the wrong position but not correcting and b) when it got to the correct height it tried to switch off.
I am therefore left with the relay and the EHC. I haven't seen any info about these failing, just notes that the relay needs to be replaced with the compressor. I have also seen that the original relay (which I think I have) was discontinued and replaced in 2008. So a couple of questions:-

1) Does anyone have any experience of relay and/or EHC testing, fault finding
2) Where are they located on the car?
3) Anyone have any other suggestion as to the problem?

I am basically car less at the moment because without the compressor I just get lower and lower. Taking the covers off and 'jumping it from the battery isn't very practical on a daily basis!

Incidentally I seem to have the broken wires in the tailgate hinge problem as well.

Any advice will be greatly appreciated.

vesil

Graben, Thank You for valuable information

I have not seen error for several weeks, but project is coming - Sooner or later. Dealer already diagnosted faulty compressor during last service check, but I did not accept their offer about 1000 EUR. Instead I will order unit for Germany, install it myself and same some 600?.

Graben

Hi Mothman,

How long does it take your compressor to raise the car up? For the new compressor I just installed, it now takes no more than 3-10 seconds for the compressor to raise the car after adding weight. My understanding is that the compressor gets less efficient over time because of the seals degrading due to wear and moisture.
For me, it was a gradual decline in rear suspension performance that finally became a regular fault message every time an extra passenger or load was added. I could hear the compressor running for a long time (30 secs or more). Also, after these long runs, the compressor is shut down for safety sake and will not operate for a period of time. A running compressor does not always mean it is working properly and making sufficient pressure.

Good luck.

karman1977

there can be also problem with relay. after engine start compressor should start (hear some noise at rear right corner)
i check on my ride, compressor due safety should be stopped after 1min45sec running, if in this time rear not lift at required height then error apear at Idrve screen. also i have problem that compressor even dont start and after 2minutes error apear, so relay dont give a 12v pover to compressor. there was no error about relay, only leveling system malfunkction.
relay for compressor locates into trunk under spare wheel compartment.

PIT M3

Hello guys,
a very interesting thread ! I read it already one year ago, but since I never had problems I did not care about this problem..

Up to now I never get a warning on I-drive, but I noticed that right rear end gets lower than left end when car is parked...

Starting the car it lifts up the right side after a few seconds, but I am not sure what´s the reason for only lowering right side when car is parked?

I will replace suction hose by aftermarket braided hose at all, but I am sure that this is not the reason..

What could be the reason? I think if pressure hose to right side is not tight, the compressor would run permanent - right ? This would cause a warning !?

Or could it be the valve itself?

Please share your thoughts with me!

Thanks Peter

btw.: The pressure hoses are standard compressed air hoses (quick coupling connections)?

karman1977

check connection between valve block and air spring. maybe some air leak at feeding hose
or
air spring is damaged.
and at side of valve block is hole with mettalic ball, what i think maybe this is like relief valve, check it also for air leak.

PIT M3

Thanks,
I will check these points.
Regards Peter

micloi

My mechanic checked mine today and it was indeed cracked in 2 places!
Replaced with a high pressure hose

Also changed both thermostats and my temperature went up from around 78 to 96ish.

Finally checked the rear drains for the sunroof and they were not clogged which was a surprise after 6 and a half years!

tom_il

Reading this topic, I checked my hose today and i looks like i have the new one. My car is a 2007 pre LCI. Can anyone confirm i have the new one ?

Photo :

mmitev

you have the new one
the old one was just rubber